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Subject: Re: [PATCH v6 2/2] Input: cros-ec-keyb - Expose function row physical map to userspace
From:   Stephen Boyd <swboyd@chromium.org>
Cc:     dianders@chromium.org, Philip Chen <philipchen@chromium.org>,
        Benson Leung <bleung@chromium.org>,
        Enric Balletbo i Serra <enric.balletbo@collabora.com>,
        Guenter Roeck <groeck@chromium.org>,
        Lee Jones <lee.jones@linaro.org>, linux-input@vger.kernel.org
To:     LKML <linux-kernel@vger.kernel.org>,
        Philip Chen <philipchen@chromium.org>,
        dmitry.torokhov@gmail.com
Date:   Thu, 14 Jan 2021 18:39:03 -0800
Message-ID: <161067834304.3661239.10444715775164261177@swboyd.mtv.corp.google.com>
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Quoting Philip Chen (2021-01-14 18:30:31)
> The top-row keys in a keyboard usually have dual functionalities.
> E.g. A function key "F1" is also an action key "Browser back".
>=20
> Therefore, when an application receives an action key code from
> a top-row key press, the application needs to know how to correlate
> the action key code with the function key code and do the conversion
> whenever necessary.
>=20
> Since the userpace already knows the key scanlines (row/column)
> associated with a received key code. Essentially, the userspace only
> needs a mapping between the key row/column and the matching physical
> location in the top row.
>=20
> So, enhance the cros-ec-keyb driver to create such a mapping
> and expose it to userspace in the form of a function_row_physmap
> attribute. The attribute would be a space separated ordered list of
> row/column codes, for the keys in the function row, in a left-to-right
> order.
>=20
> The attribute will only be present when the device has a custom design
> for the top-row keys.
>=20
> Signed-off-by: Philip Chen <philipchen@chromium.org>
> ---

Reviewed-by: Stephen Boyd <swboyd@chromium.org>